The present invention relates to a coupling device for a torque transmitting, longitudinally displaceable coupling for two shaft parts having toothed profiles.
A coupling device of this type is disclosed by German Patent Specification No. 3,729,393, which serves to keep the toothed profiles of both shaft parts largely free from backlash while maintaining an axial mobility of the shaft parts, coaxial to one another, in their peripheral direction.
The coupling part coupling the two shaft parts to one another so as to be fixed in terms of rotation is here formed by a hub-like end piece of one shaft part which is slit like a collet at a free end area thereof. This end piece is equipped with an internally toothed profile which meshes with an externally toothed profile of a meshing part overlapped by the hub-like shaft end piece and provided so as to be fixed in terms of rotation on the other shaft part. This meshing part is formed by the end piece of the other shaft part projecting into the hub-like end piece of one shaft part.
In order to keep mutual meshing of both toothed profiles free from backlash in the direction of rotation of the shaft parts, a clamping member, such as a slightly conical annular spring, which can be pressed against a stop while both shaft parts are thrown into mutual mesh, sits on the end area of the hub-like end piece of one shaft part which is slit like a collet. A radially directed clamping force is thereby produced on the hub legs formed by the slitting of the hub-like shaft end piece to provide segment-shaped in cross-section. This clamping force presses these hub legs, with their internal tooth system, into spaces of the external tooth system of the other shaft part in order to keep adjacent meshing of the toothed profiles in contact with one another in a manner free from backlash.
In a further coupling device of similar design disclosed by German Utility Model No. 6,933,918, a clamping member, which forms a ring for overlapping the slit, hub-like shaft end piece, is conically widened on the inside in a clamping direction and further overlaps the segment-shaped hub legs in a positive-locking manner.
To produce a radially directed clamping force acting on the hub legs, the ring, via a compression spring bearing against the accessible ring end face, is supported on a clamping member which is formed by a sleeve overlapping the slit, hub-like shaft end piece and screwed onto the external thread of the same so as to be locked against rotation.
Therefore, an object of the present invention is to provide a coupling device in which a backlash free meshing of toothed profiles is achieved.
In this coupling device, it is to be possible, in particular, to couple shaft parts to one another which are equipped with toothed profiles of various design and/or have different diameters.
The coupling device according to advantageous embodiments of the present invention is thus distinguished by an intermediate bush which is arranged between both shaft parts to be coupled to one another, is in mesh with their toothed profiles and has a collet-like design at both end areas. In this arrangement, when one slit front end of the intermediate bush is pressed against the stop, the same, by radial expansion, is thrown into positive locking mesh with the internally toothed profile of the hub-like shaft part, and its other slit front end, when interacting with the clamping member, is thrown by radial compression into positive-locking mesh with the externally toothed profile of the other shaft part.
The intermediate bush here forms a reducing piece which, at the outer and inner periphery, can facultatively be equipped with toothed profiles differing from one another, depending on whether the shaft parts to be couple have the same or different toothed profiles. The intermediate bush thus enables shaft parts to be coupled which have different types of tooth systems, for example DIN and SAE tooth systems. In addition, the invention provides the important advantage that both shaft parts can be at least largely separated vibrationally from one another provided the intermediate bush is made from a suitable material, for example, glass fiber-reinforced plastic.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.